Topical instillation of eye drops into the lower cul-de-sac is the most common method for the administration of the ophthalmic drugs. However, one of the major problem encountered with eye drops is the rapid and extensive elimination of drugs from the precorneal area by the protection mechanisms of the eye, resulting in a poor bioavailability. The use of lipid nanoemulsions has been considered as a promising strategy to improve the bioavailability of ophthalmic drugs instilled
topically. Therefore, the objective of this review is to present different aspects related to composition, preparation methods and physicochemical properties of the nanoemulsions in ophthalmic delivery systems. The influence of nanoemulsions on biopharmaceutic aspects of cyclosporin A, indomethacin and pilocarpine is also discussed.